According to the Chinese theory of the five elements, the material world is made of five elements: wood, fire, earth, metal and water. These five elements are thought to make up the daily life of mankind.
The Chinese theory of the five elements is similar to the Greek theory of the four elements, which are fire, earth, water and air. According to the Chinese theory, wood generates fire, fire generates earth, earth generates metal, metal generates water, and water generates wood, in a cycle.
On the other hand, wood restricts earth, earth restricts water, water restricts fire, fire restricts metal, and metal restricts wood. Chinese theory maintained that there should be a balance of all five elements. Excess or insufficiency of any of the elements would result in abnormal restrictions.
The wood element controls the liver, fire controls the heart, earth the spleen, metal the lungs, and water the kidneys, according to the theory. The wood element is associated with the sense of sight, fire with the tongue, earth with the mouth, metal with the nose, and water with the sense of hearing. Wood is associated with anger, fire with joy, earth with overthinking, metal with grief, and water with fear.